The present invention relates to heat exchangers that are generally configured comprising a number of internal fluid or gas passages disposed within a surrounding body. In an example embodiment, the internal passages are provided in the form of tubes that are designed to accommodate passage of a particular fluid or gas in need of cooling, and the body is configured in the form of a shell or casing to accommodate passage of a particular cooling fluid or gas used to reduce the temperature of the fluid or gas in the internal passages. A specific example of such a heat exchanger is one referred to as a shell and tube exchanger, which can be used in such applications as charge air pre-coolers for use with internal combustion engine systems that make use of a turbocharger or supercharger to boost the pressure of the intake charge directed to the engine for combustion.
Referring to FIGS. 1 and 2, a prior art shell and tube heat exchanger 10 generally includes a casing or shell 12 that includes an internal chamber 14 extending between opposed open axial ends 16 and 18. A plurality of individual tubes 20, i.e., internal passages, are disposed within the internal chamber and are aligned adjacent one another in a spaced apart orientation by use of two tube plates 22 and 24. The tube plates 22 and 24 are positioned at respective open axial ends 16 and 18 of the case 12, and the tubes are sized so that tube ends are positioned adjacent the respective tube plates. The tube ends are sealed to the tube plates to form a leak-tight connection therewith.
The tube plates 22 and 24 are interposed between each shell axial end and a respective inlet and outlet manifold 26 and 28. The inlet and outlet manifolds 26 and 28 are joined to the shell axial ends 16 and 18 by conventional methods, such as welding, brazing, or the like, and are configured to facilitate attachment of the heat exchanger with an air intake system of an internal combustion engine, and to facilitate passage of a liquid or gas to be cooled to and from the plurality of tubes.
The shell 12 includes an inlet connection 30 and an outlet connection 32 that are each attached to a wall surface of the shell, and that are used to facilitate the passage of a cooling medium, fluid or gas, into and out of the shell internal chamber 14. A baffle 34 is disposed within the shell and comprises a plurality of openings to accommodate the passage of the tubes therethrough. The baffle is attached within the casing internal chamber by welding, brazing or the like. The baffle extends radially a partial distance within the internal chamber, and is used to control the flow path of cooling medium within the chamber so that it flows in one radial direction from the inlet connection 30 over a first section of the plurality of tubes, and then flows in an opposite direction over a second section of the plurality of tubes to the outlet connection 22.
Accordingly, such known shell and tube heat exchangers have a construction comprising three components that include the shell and the two tube plates. The use of such a multi-part assembly requires that each such part be independently manufactured, as well as requiring that each of the parts be assembled together. The need to manufacture and assemble these independent parts increases the overall cost of constructing a heat exchanger.
Additionally, the use of these independent parts requires that the manufacturing process have a high degree of accuracy to ensure that the parts fit together properly. Further, the use of such independent parts requires that, during the assembly process, appropriate measures be taken and time spent to ensure the formation of a leak-tight seal between the tube plates and shell. Further, the use of such known shell and tube heat exchanges requires that additional time be spent to correctly position and attach the baffle within the shell.
It is, therefore, desired that a heat exchanger be constructed in a manner that reduces the overall number of components to facilitate manufacturing and assembly efficiency. It is further desired that such heat exchanger be constructed in a manner that reduces the potential for leaks occurring between the shell and the tube plates. It is further desired that such heat exchanger be constructed in a manner that facilitates the process of mounting and/or attaching a baffle therein to further improve assembly efficiency. It is further desired that such heat exchangers be constructed using materials and methods that are readily available to facilitate cost effective manufacturing and assembly of the same.